﻿using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace number
{
    class Program
    {
        static void Main(string[] args)
        {
            Console.WriteLine("输入第一个数");
            int a = Convert.ToInt32(Console.ReadLine());
          
            Console.WriteLine("输入符号");
            char str = Convert.ToChar(Console.ReadLine());
            Console.WriteLine("输入第二个数");
            int b = Convert.ToInt32(Console.ReadLine());
            switch (str)
            {
                case '+':
                    Console.WriteLine("两数之和是{0}",a+b);
                    break;
                case '-':
                    Console.WriteLine("两数之差是{0}",a-b);
                    break;
                case '*':
                    Console.WriteLine("两数之积是{0}",a*b);
                    break;
                case '/':
                    Console.WriteLine("两数之商是{0}",a/b);
                    break;
                default:
                    Console.WriteLine("请输入正确符号");
                    break;

                
            }
        }
    }
}
